This is a comprehensive research proposal which is designed to improve the treatment of children with cancer by conducting clinical investigations as a member of Childrens Cancer Study Group (CCSG) and by independently conducting other research which is directly related to the mission of CCSG. The Childrens Hospital of Los Angeles (CHLA) is a major pediatric referral center for the Pacific Southwest and has one of the largest pediatric oncology services in the nation. An inter-departmental program has developed at CHLA which involves basic and clinical scientists and has evolved into a multidisciplinary model for the management of pediatric cancers with representation from the disciplines of Pathology, Surgery, Radiation Therapy, Radiology, Nuclear Medicine, Virology, and Hematology-Oncology. The participation of the investigators of CHLA in CCSG enables quantitative comparative clinical investigations aimed at establishing the best mode of any cancer therapy. This approach has been highly successful for acute leukemia and to a lesser degree for those childhood solid tumors where sufficient numbers of comparable cases are available. The unique resources of CHLA will permit the development of new therapeutic approaches as background for group-wide application. These include promising new drugs as developed as part of CHLA participation in the NCI Phase I Working Group, new dose schedules and combinations of established agents predicted by in vitro and in vivo pharmacological studies, immunological characterization of selected neoplasms, intensive chemotherapy in the protected environment, and approaches to psychosocial rehabilitation of the pediatric cancer patients and family. The program at CHLA will seek as its ultimate goal a comprehensive therapeutic and investigative approach to childhood cancer.